Dead sharks? Edible statues? Contemporary artists rely on exotic materials to push the boundaries of art. And they're using a new breed of conservators to fix things when they go bad.

Forget the white coats, Forget the magnifying glasses and tiny brushes. Sure, classical art conservators still spend their days and nights obsessing over ways to remove centuries of grime from Renaissance frescoes, but contemporary art preservation is an entirely different picture. After all, how do you save a putrefying shark? How do you deal with an avant-garde video installation that's blinking out? And what do you do when the industrial-grade fireworks stuffed in the headless cow carcass stubbornly refuse to light? Modern art represents the Wild West of art preservation -a world in which artists push the envelope with outrageous ideas and materials, and conservators use any means necessary to keep those works in one piece and on display.

We asked top pros to share the inside stories behind some of the most outlandish and challenging conservation projects. Norman Rockwell paintings these ain't.

"The Physical Impossibility of Death in the Mind of Someone Living" by Damien HirstThe shark was, well, rotting. Despite its portentous title, Damien Hirst's 1991 masterwork was pretty straightforward: a dead tiger shark suspended in an acrylic glass tank filled with 224 gallons of water. The problem was that the huge fish began to decompose almost immediately -Hirst had failed to preserve it properly. To stem the stench, London's Saatchi Gallery pumped bleach into the water, but that only made the shark decompose faster. None of this stopped an American hedge-fund manager from buying the work for $8 million in 2004, making it one of the most expensive contemporary art sales ever.

An almost comical series of attempts to preserve the putrid predator ensued. Hirst and his conservators had the shark skinned and its hide tanned and mounted onto a fiberglass skeleton. But the result, intended to inspire terror, looked like a rejected prop from Jaws 3-D.

So Hirst threw in the fish towel. He struck a deal with the buyer: For a six-figure fee, he simply acquired another dead shark from an Australian fisherman, and this time preserved it with formaldehyde. Shark number two is a foot shorter, but its gaping jaws are wider and scarier. If all goes well, it will last 250 years. "That piece is like the Sistine Chapel, it's so iconic," says Gwynne Ryan, sculpture conservator at the Smithsonian's Hirshhorn Museum, who has worked on other Hirst pieces. "Will we look back on all these changes and say: 'God, what a ridiculous thing to do?' It's kind of hard to know."

As for shark number one? It went from a multimillion dollar artwork to 1,800 pounds of biological waste in the blink of an eye.

"Video Flag" by Nam June PaikEven back when cathode-ray tube (CRT) televisions were the norm, repairing one was a headache. It meant hauling the heavy box to a cluttered shop, where a guy named Murray in a stained shirt would place it on a shelf, and then call you two weeks later with a Kansas-sized bill. Now imagine having to fix 70 of them, with the added problem that CRTs are obsolete and Murray is retired or dead.That's what Jeff Martin, another Hirshhorn conservator, is facing with Nam June Paik's "Video Flag," a kaleidoscopic wall of 13-inch Sanyo CRTs that evoke the United States and its flag. So far, Paik's 1986 masterpiece has held up well, but some of the monitors, just like your grandma's old set, are well past their warranties. "They're electronics, and they wear out," says Martin. "What happens when they all need to be replaced?"

Since CRT monitors are no longer being made, buying new ones from Best Buy isn't an option. Nor is substituting modern TVs; that fuzzy scan-lined picture that made you dump your old CRT for for a plasma or LCD screen is inseparable from the piece's conception. Worse still, putting the exhibit in protective storage and hauling it out every ten years or so isn't an option: The TVs need to be powered up periodically or the diodes break down chemically.

So what are the folks at Hirshhorn doing? They're stockpiling old CRTs like mad for use as spares. But as Ryan points out, "There are only so many CRT monitors in the world. Our conservators are going on eBay like crazy people to buy them up. And they're already running out."

"Building Steam 190" by Donald LipskiAn industrial rubber glove filled with rice, then capped off with a porthole for people to peer inside... sounds like a disturbing artifact you might find in a German tourist shop. For the private collector who bought this work by enigmatic modernist sculptor Donald Lipski, however, it was disturbing on a whole other level.

The first problem: After only a few years, the glove ripped. Even worse, the rice became infested with the larvae of tiny cigarette beetles. It was up to Glenn Wharton, a conservator now with the Museum of Modern Art, to tell the collector the bad news: Two-thirds of the artwork -the glove and the rice- would have to be replaced.

Restoration went well at first. Lipski told Wharton where to find an exact duplicate of the glove and even sent him imported specialty rice (apparently Uncle Ben's wouldn't cut it). Wharton then subjected the grains to a freeze-thaw-freeze cycle to kill any latent infestations. Victory! The piece went back on display. But, two years later, Wharton got another call: The rice was infested again, this time with a far-gnarlier breed of lice. At this point, Lipski suggested replacing the rice with ricelike plastic "sprinkles" that he had considered using originally.

"I had a hard time with this," Says Wharton. "Here's an artist coming many years later saying, 'Let's just change the material aspect of the work.'" After much discussion with Lipski and the owner, the necessary changed were made, but Wharton and his associated suggested that the date of the work be amended to reflect the modifications. Case closed, but due diligence still doesn't tell us what we really want to know about "Building Steam." Why?

"Palimpsest" by Anne HamiltonGreat art may be timeless, but when the theme of the work is how memory fades over time, conservators know they're in for some kind of special meta-Hell. "Palimpsest" is a room wallpapered from ceiling to floor with thousands of tiny faded notes written by the artist's friend, some buried in beeswax. To complete the uplifting message that we're all headed for senility, there's also a tank of snails chomping contendedly on two heads of cabbage.

"It requires a whole village to put this thing together," says Ryan, who is overseeing the work's installation at the Hirshhorn, the third time it's been recreated. And while the piece is a bear to assemble, the biggest hurdle is, believe it or not, legislative. Since the work's initial showing in 1989, snails have been classified as pests by the government. "You have to get special permission from the U.S. Department of Agriculture," Ryan explains. "And then you have to prove you're not just going to unleash them into the wild afterwards."

The last time the work was on display in 2005, getting the clearance took longer than expected, and the exhibit opened with replacement mollusks: a selection of garden-variety slugs dug up from the lawns around the museum. When the snails finally did arrive, their treatment was appropriately high-concept. The staff gorged them on fresh veggies, then rotated them in and out of the exhibit on a precise schedule. The snails had it pretty good, in fact, until the end of the exhibit's run, when, in accordance with the law, they were executed by autoclave. So much for preservation.

(Image credit: Janine Antoni/Luhring Augustine)

"Lick and Lather" by Janine AntoniThe strange thing isn't that Antoni made a hyperrealistic impression of her upper body using dental molding materials. Or that she cast a series of busts, 14 in chocolate and 14 in soap. Or even that, to mimic the effects of aging, she licked the chocolate and bathed with the soap. What's strange is that at no fewer than three galleries (in Venice, Dublin, and Philadelphia), visitors have bitten the noses off the chocolate sculptures. Afterward, there was real discussion about leaving them that way. "Do you repair it?" asks Ryan. "Or does that make this one unique?"

The decision was made not to repair the noses (or prosecute the offenders). But as the components age -handmade soap has a shelf life of only three years and chocolate not much longer- "Lick and Lather" continues to pose prickly conceptual questions. "What happens if the artist is no longer around?" wonders Ryan. "The busts can be recast. But who bathes with it?"

Why bother repairing or restoring them? Aren't certain pieces and schools transient by nature? Restoring them completely defeats the purpose of the work. I say let them rot and move on. These works are a product of our society and reflect that. They are disposable art from disposable artists.

@EdwardSanc: all kinds of dead animals are put on display - ever heard of taxidermy? Similarly all kinds of animals are killed. It's a fairly important step in the production of meat.

As for humans, look up Gunther von Hagens and plastination. While no humans are killed specifically to be put on display, he uses real dead people in his art. Most cultures in the world are fascinated with life, and are often just as fascinated with death. It's why art like this exists.

Fish are caught and killed in their millions, and the people who do it make money, and their profits and taxes do 'lots and lots of good'. My point? A shark is a fish. It's a big one, yes, but still a species of fish. Why should we give a big fish any more (or less) respect than a small one? Why do we eat cows but not dogs or dolphins? There simply is no good reason. Presumably dogs are tasty (I wouldn't know), but we all choose to be 'speciesist' to some degree, and rather than scorn it the majority (every non-veggie in the world) accepts that certain animals are treated differently.

Next time you use an insect spray, be sure to think about your speciesism against insects. Don't they have a right to life too? Or if you think it's okay to kill them, do you also eat insects as part of your daily diet?

I think my rant is over, but the words 'double standards' spring to mind, or even 'people in glass houses shouldn't throw stones'.

Terrible to see the property status of an individual, especially one killed to be on display. Would we accept that if he were a human, a dog or a dolphin? Most of us would scorn at it.

This is the discrepancy caused by speciesism and my hope is that in 250 years we'll look back in the same way that we not look back at slavery, nazism, sexism etc - we'll be horrified how we could pay money to have someone killed to be put in a glass jar, at a time when the world could use that money for doing lots and lots more good.